System of control



WE'TNESSES:

CONTROL @are TML/2 M @my Patented July 31,' 1923.

UNITED STATES REESE T. KINTZING, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR T WESTING# HOUSE ELECTRIC ik MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- valen.

SYSTEM OF CONTROI'J.`

Application led October 27, 1920. Serial No. 419,874.

To all whom 't may concern:

Be it known that I, Rnnsn T. KINTzINc, a citizen of the United States, and a resident of Vilkinsburg, in the county of Allegheny and State of Pennsylvania, have in- Vented a new and useful Improvement in Systems of Control, of which the following is a specification.

My .invention relates to control systems, and it has particular relation to such systems of control as apply to tandem-operated devices.

One object of my invention is to provide means whereby the number of machines, or motors, or other devices, to be operated in tandem, may be readily controlled by the operator, which means is additional to the main-line switch for each machine. The manipulation of these switches will determine the combinations that are possible to be operated in the tandem-connected machines.

Another object of my invention is to provide a central control station for the tandem-connected machines, from which complete control o the entire set of machines is obtainable at all times.

I Another object of my invention is to provide asimple and elicient means for readily determining the number or" machines to he operated in tandem.

@ne specific instance of the use ont a sys;

tem of tandem-connected machines is in the treatment of textile fabrics, where, in the cloth-finishing processes, it is desirable to connect in tandem driers, tenters, mangles, calenders, etc. Some cloths do not require as 'many treatments as others and, accordingly, at times all of the machines do not needto he used.

lleretofore, in control schemes for tanq dem-operated systems, two methods of control have been devised. @ne is an individual control for each motor. The second is a central drum type controller that was designed to shift the various circuit connec- `tions. y

The present invention provides a simplilied and more conveniently operated` central control station for controlling all of the ma chines in one operation, and is shown as a central, push-button control station, the circuit connections of which are common to all of the machines. Across the line of each motor is a low-voltage relay, and the relays, in turn, are connected in parallel relation in the push-button control circuits.

Each of the motors is also provided with an overload relay, and these relays have their contact members connected in series in the control circuits, so that an overload occurring on any one machine will cause an interruption of the circuit through all of the motors.

There are additional auxiliary control stations for stopping the machines located on the individual machines. These are, in no way, essential to the central control station circuits, except in cases where the machines have been stopped by one of these auxiliary switches. ln this event, the central control station cannot begin the operation ot' the machines until the open auxiliary switch has been closed. This is, of course, a well-known protective measure.

The present invention is set forth in the accompanying drawings, wherein Figure l is a diagrammatic view of control circuits and apparatus embodying my invention;

Fig. Z is a schematic view of the principal circuits; and

3 is a sequence chart, ot well-@own torni, indicating the order of the closure or" the switches.

Rei-erring to Fig. l, three compoundwound motors l, 2 and 3 are shown, each having a series ield-magnet winding a and a shunt field-magnet winding 5, a starting" resistor 6 being also provided for each motor. Current is supplied to these motors :rom a source of energy through conductors 7 and a plurality olf lrnife-blade switches 8. The current for the control circuits is talren from the main-line conductors 'l' through a limite-blade switch 9.

lt will he understood that as many motors as are desired may be connected in the manner about to be described but, in the present instance, it has heen regarded as sucient tor explaining my invention to show three motors. lt may be assumed that all of the imite-blade switches 8 and 9 have heen closed.

A central push-button control station is shown, having an inch button l0, a starting hutten il, and a stop ,button 12. Inch button l0 he connected in any of the for the motors. As the operation of this switch is well known, and completes control circuits which are identical with those of the vstarting button, no endeavor will be made to describe the circuits completed through the inch button 10.

When the starting button 11 1s depressed, it bridges contact members 15 to complete a circuit which extends from control bus-wlre 16 (in circuit with the knifeblade switch 9), through the push-button swltches 12 and 10, to the conductor 17. From this point, the circuit extends through the normally closed contact lmembers of overload relays 18, 19 and 20 of the first, second and third motors, respectively, thus connecting these relays in series in the control circuit. Consequently, should an overload occur on any one machine, the circuit will be broken through the entire number of machines, and all will immediately stop.

As is indicated in dotted lines in the third panel, the circuit being traced would continue through the entire number of machines to be connected in tandem until the last machine was reached, where a link, or bridging wire 21 would extend across terminals 22 and 23 that are located, respectively, in the circuit across the overload relay 20 and the circuit of the coil 250i the low-voltage relay 26. In the drawing, therefore, the link 21 is actually employed in connection with the third machine.

A corresponding set of terminals 22 and 23 are to be found in the control circuits for motors 1 and 2. Referring now to motor 3, this link or bridging wire 21 permits the current to flow through resistor 24, coil 25 of the low-voltage relay 26, conductor 27, and control conductor 28, thereby energizing coil 25 t0 close relay 26. It will be noted that the coils of the corresponding lowvoltage relays 26 of motors 1 and 2 are connected in parallel relation in this same circuit. This connection may be traced for motor 2 from the junction of conductor 29 with control bus-wire 42, through resistor 24, coil 25, and conductor to control buswire 16. For motor 1, the corresponding circuit includes conductor 31, resistor 24, coil 25, and conductor 32. These circuits being simultaneouslyenergized, all of the relays 26 will close simultaneously.

From -this point, the circuits for each motor areldentical, and, for the sake of simtions that are common to plicity and clearness, these circuits will be described for motor 3 alone. Where circuits for motors 1 and 2 correspond to those of motor 3, they will be given like reference numerals.

The .relays 26 being closed, a circuit is completed through the contact members of the relay 26 and the coil of the main-line contactor 33, thereby closing this contactor. The closure of the contactor 33 permits current to traverse a circuit comprising the series field winding 4, armature of motor 3, starting resistor 6, actuating coil of switch 34, contactor 33 and the actuating coil oi the overload relay 20. The motor then operates.

Upon release of the starting button 11, a holding circuit for the coil of contactor 33 is completed from control bus-wire 35 through conductor 36, and auxiliary contact members of the relay 26.

The coil of the switch 34 being in the armature circuit, the counter-electromotive force built up therein will reduce the current through this coil until it reaches a point where the force of gravity will overcome the force exerted by the coil, and the switch 34 will close. This action completes a circuit tothe coil 38, closing this switch to shunt the starting resistor and accelerate the motor. For further acceleration, the fieldresstor 39 may be inserted in the shunt field circuit in accordance with any of the now well-known methods.

I t Will be noted ithat the acceleration switch of the central control station in Fig. 1 is closed. If the slow switch should be opened, the circuit to the coil 38 would be broken at this switch and the motors would operate at slow speed with the starting resister in circuit with the armature.

Occasionally, conditions arise on an individual machine which neceitate the stopping of that machine promptly, and, in tandem-operated machines, the entire group should be stopped simultaneously to prevent damage to the material, such as cloth, being operated upon. Hence, in the present system, start and stop switches are located at convenient points about the machines, which will permit the attendant at each machine to promptly stop the entire group of machines upon the occurrence of some condition which should be corrected. Such control stations are located in the circuit through the start and stop buttons of the central control station and are conventionally shown in Fig. 1, as switches v4() and 41. The operation of these switches is so well understood that further reference need not be made thereto. From the above description, it will be a parent that, inasmuch as the coils 25 of t e low-voltage relays 26 are connected in parallel relation to the control system connecal of the machines, and the overload relays are connected in series relation with such control system connections, a single, central, pushbutton control station may be provided for a -plurality of motors. Therefore, the operation of the apparatus at' this central station will affect all of the machines simultaneously to start, or stop, or control the speed thereof. This arrangement is an improvement over existing control systems for tandem-operated machines. It not only greatlysimplilies thev control system and reduces to a minimum the possibility of serious damage to motors and material by the operators, but greatly decreases the cost of such systems by reducing, in a large measure, the working apparatus.

By reason of the fact that terminals 22 and 23 are provided-in the control circuit for each of the motors, the link 21 may be inserted in any set of terminals. The location of link 21 will definitely determine the total number of machines which lmay be operated in tandem. As has been noted, the present instance illustrates three machines operating in tandem, and controlled by the central push-button station. Had the link 21 been placed in the circuit of the second motor, motor 3 would have been cut out and the K current crossing the overload relays 18 and 19 would have been diverted through 'the coil 25 of the relay 26, for the second motor at terminal 22 for this motor.

The convenience of being able to accomplish this result is of material assistance in mills Where the materials treated may be subjected to a number of dilferent processes. Some materials require more processes than others, and the provision of the terminals 22 and 23 for each motor furnishes the most convenient method of controlling the number of machines to be operated in tandem.

Furthermore, it may be desired to omit one or more machines from the tandemoperated group.

Assume, in the present illustration, that it is desired to omit machine 2. lt is only necessary to open the main-line knife-blade switch 8 for that machine, `which will prevent current reaching the armature thereof. However, this action will in no way inter-lere with the control circuits because the overload relays i8, i9 and 2() that are located therein are normally closed, and the circuit through themV is continuous, so that current 'will continue to cross the overload relays of as many machines as are connected together until the link 21 is encountered, irrespective of Whether the main-line switch is closed or open.

l do not Wish to be restricted to the speci-lio circuit connections or arrangement of parts herein set forth, as various modiiications thereof may be effected without departing from the spirit and scope of my invention.

I desire, therefore, that only such limitations shall be imposed as are indicated by the ap nded claims.

claim as my invention 1. In a multiple-unit control system wherein the vunits are mounted in tandem, the combination with means for controlling the various units simultaneously, of means comprising a single transferable switching member for determining the number of units 4.-. In a motor-control system for a 4plu:`v

rality of motors, the combination with a manually-operated control station having appropriate circuits therefor, of a plurality of low-voltage relays connected 'in parallel relation in said circuits,v and a plurality of overload relays connected in series relation in said circuits.

5. ln a control system for a plurality of tandem-operated motors, the combination with a central control station therefor, of means comprising mingle transferable switching member for determining the numloer of motors to so operated.

d. ln a control system for a plurality of translating devices, the combination with control circuits therefor, ol governing means for each device controlled by the value of the applied voltage, and additional governing means for each device controlled by the value of the current traversing it, said meansV being respectively connected in parallel and in series rele said circuits.

"d". a con system for a plurality of motors, the co oinetion with a control circuit for said motors, of governing means for each motor controlled by the value of the applied voltage, said means being connected in parallel relation in said control circuit.

8. a control system 'for a plurality oil translating devices adapted to be operated' in tandem, the combination with control cuits therefor, governingmeans for each do vice controlled by the value ci, the applied voltage, and additional overning means 'for eaclidevice controlled y the value of current traversing it, said means lacing spectively connected in parallel in seid-,es relation in said circuits, of means for deter llo? mining the number of such devices to be operated.

9. In a control system for a plurality of motors, having a central control station with 4connections common for all of the motors, the combination with low-volt relays connected in parallel relation with said connections and overload relays connected in series relation with said connections, of a terminal in the actuating circuit foreach of the low-volt relays, a second terminal in the controlle circuit across each of said overload relays, and means for connecting any pair of terminals to determine the number of motors to be operated from said control station.

10. In a control system for a plurality of tandemoperated devices, having a central control station with connections common to all of the devices, the'combination` with lowvoltage relays connected in parallel relation thereto and overload vrelays connected in series relation therewith, of a terminal in the controlling circuit for each of the low-voltage relays, a second terminal in the governed circuit across each of said overload relays, and means for connecting the pair of terminals for any device to determine the number of devices to be so operated.

11. In a control system for a plurality of motors having a central control station with connections common to all of the motors, the combination with a low-voltage relay and an overload relay for each motor, of a contact member in the actuating circuit for each low-voltage relay, a second contact member in the controlled circuit across each overload relay, and means for bridging any pair of contact members.

12. In a control system for a plurality of tandem-operated motors, the combination with common control means therefor, of means comprising a single transferable link for selectively determining the number of motors to be so operated.

In testimony whereof, 4I have hereunto subscribed my name this 14th day of October, 1920.

REE SE T. KINTZING. 

